"I think we are going to wait till this summer. Our life is always like a treadmill with Elton constantly working and touring. But when we go away to our house in France, that's when we sit back and go, 'OK, how is this working, how are you feeling?'"

Elton had previously confirmed that neither he nor David know who the biological father of Zachary is as they both donated sperm to the surrogate mother - something they intend to repeat for their second child.

Zachary's mum remains unnamed and Furnish stressed that because of the impact on her own family they may find an alternative surrogate mother.